bugfix _map.SetCenterLatitudeLongitude and _map.UpdateMap() with CultureInfo

[izabala033]

When using _map.SetCenterLatitudeLongitude(), this function saves the current latitude and longitude as string. It uses stringFormat to cast Vector2d x and y to string, but doesn't use InvariantCulture like it does at line 319, inside Initialize().
Decimal separator depends on the culture but InvariantCulture uses . which is what you want. In some cases , is used.
The problem is that it was saving Vector2d(1.2, 3.4) as "1,2, 3,4" instead of "1.2, 3.4. This raises an error when using _map.UpdateMap(), when using Conversion.StringToLatLon(). A split is made with "," as separator, raising an ArgumentException("Wrong number of arguments") because the number of arguments are 4 instead of 2.

[theolagendijk]

I came to this same fix when a client run into an issue with my app on an iPhone running with Dutch language settings.

Perfect bug fix for a nasty problem. I would highly recommend that this fix get's pulled in to the main repository. Small change huge improvement for international audience.